Method and apparatus for an adjustable damper

ABSTRACT

A vehicle suspension damper is described. The vehicle suspension damper includes: a pilot valve assembly; a primary valve; and an adjuster, wherein the pilot valve assembly meters fluid to the primary valve, and the adjuster moves the primary valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and claims priority of U.S.provisional patent application Ser. No. 61/709,041, filed on Oct. 2,2012, entitled “METHOD AND APPARATUS FOR AN ADJUSTABLE DAMPER” byEricksen et al., assigned to the assignee of the present application,and is hereby incorporated by reference in its entirety herein.

This application claims the benefit of and claims priority of U.S.provisional patent application Ser. No. 61/667,327, filed on Jul. 2,2012, entitled “METHOD AND APPARATUS FOR AN ADJUSTABLE DAMPER” byEricksen et al., assigned to the assignee of the present application,and is hereby incorporated by reference in its entirety herein.

This application is a continuation-in-part application of and claims thebenefit of co-pending U.S. patent application Ser. No. 13/485,401, filedon May 31, 2012, entitled “METHOD AND APPARATUS FOR POSITION SENSITIVESUSPENSION” by Ericksen et al., assigned to the assignee of the presentapplication, and is hereby incorporated by reference in its entiretyherein.

The application with Ser. No. 13/485,401 claims the benefit of andclaims priority of U.S. provisional patent application Ser. No.61/491,858, filed on May 31, 2011, entitled “METHOD AND APPARATUS FORPOSITION SENSITIVE SUSPENSION DAMPENING” by Ericksen et al., assigned tothe assignee of the present application, and is hereby incorporated byreference in its entirety herein.

The application with Ser. No. 13/485,401 claims the benefit of andclaims priority of U.S. provisional patent application Ser. No.61/645,465, filed on May 10, 2012, entitled “METHOD AND APPARATUS FOR ANADJUSTABLE DAMPER” by Cox et al., assigned to the assignee of thepresent application, and is hereby incorporated by reference in itsentirety herein.

This application is a continuation-in-part application of and claims thebenefit of co-pending U.S. patent application Ser. No. 12/684,072, filedon Jan. 7, 2010, entitled “REMOTELY OPERATED BYPASS FOR A SUSPENSIONDAMPER” by John Marking, assigned to the assignee of the presentapplication, and is hereby incorporated by reference in its entiretyherein.

The application with Ser. No. 12/684,072 claims the benefit of andclaims priority of U.S. provisional patent application Ser. No.61/143,152, filed on Jan. 7, 2009, entitled “REMOTE BYPASS LOCK-OUT” byJohn Marking, assigned to the assignee of the present application, andis hereby incorporated by reference in its entirety herein.

This application is a continuation-in-part application of and claims thebenefit of co-pending U.S. patent application Ser. No. 13/189,216, filedon Jul. 22, 2011, entitled “SUSPENSION DAMPER WITH REMOTELY-OPERABLEVALVE” by John Marking, assigned to the assignee of the presentapplication, and is hereby incorporated by reference in its entiretyherein.

The application with Ser. No. 13/189,216 is a continuation-in-partapplication of and claims the benefit of co-pending U.S. patentapplication Ser. No. 13/010,697, filed on Jan. 20, 2011, entitled“REMOTELY OPERATED BYPASS FOR A SUSPENSION DAMPER” by John Marking,assigned to the assignee of the present application, having and ishereby incorporated by reference in its entirety herein.

The application with Ser. No. 13/010,697 claims the benefit of andclaims priority of U.S. provisional patent application Ser. No.61/296,826, filed on Jan. 20, 2010, entitled “BYPASS LOCK-OUT VALVE FORA SUSPENSION DAMPER” by John Marking, assigned to the assignee of thepresent application, and is hereby incorporated by reference in itsentirety herein.

The application with Ser. No. 13/189,216 is a continuation-in-partapplication of and claims the benefit of co-pending U.S. patentapplication Ser. No. 13/175,244, filed on Jul. 1, 2011, entitled “BYPASSFOR A SUSPENSION DAMPER” by John Marking, assigned to the assignee ofthe present application, and is hereby incorporated by reference in itsentirety herein.

The application with Ser. No. 13/175,244 claims the benefit of andclaims priority of U.S. provisional patent application Ser. No.61/361,127, filed on Jul. 2, 2010, entitled “BYPASS LOCK-OUT VALVE FOR ASUSPENSION DAMPER” by John Marking, assigned to the assignee of thepresent application, and is hereby incorporated by reference in itsentirety herein.

BACKGROUND

1. Field of the Invention

Embodiments generally relate to a damper assembly for a vehicle. Morespecifically, the invention relates to an adjustable damper for use witha vehicle suspension.

2. Description of the Related Art

Vehicle suspension systems typically include a spring component orcomponents and a dampening component or components. Typically,mechanical springs, like helical springs are used with some type ofviscous fluid-based dampening mechanism and the two are mountedfunctionally in parallel. In some instances, a spring may comprisepressurized gas and features of the damper or spring areuser-adjustable, such as by adjusting the air pressure in a gas spring.A damper may be constructed by placing a damping piston in afluid-filled cylinder (e.g., liquid such as oil). As the damping pistonis moved in the cylinder, fluid is compressed and passes from one sideof the piston to the other side. Often, the piston includes ventsthere-through which may be covered by shim stacks to provide fordifferent operational characteristics in compression or extension.

Conventional damping components provide a constant damping rate duringcompression or extension through the entire length of the stroke. Otherconventional damping components provide mechanisms for varying thedamping rate. As various types of recreational and sporting vehiclescontinue to become more technologically advanced, what is needed in theart are improved techniques for varying the damping rate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A depicts an asymmetric bicycle fork having a damping leg and aspring leg.

FIG. 1B depicts a cross-sectional side elevation view of a shockabsorber of a bicycle fork cartridge, in accordance with an embodiment.

FIG. 2, FIG. 3, and FIG. 4 depict a cross-sectional side elevation viewof various operational positions of an embodiment of the base valveassembly of detail 2 of FIG. 1B.

FIG. 5A and FIG. 5B depict a cross-sectional side elevation view of avalve assembly of detail 2 of the shock absorber of FIG. 1B, inaccordance with an embodiment.

FIG. 6 and FIG. 7 each depicts a cross-sectional side elevation view ofthe valve assembly of detail 2 of the shock absorber of FIG. 1B, inaccordance with an embodiment.

FIG. 8A and FIG. 8B depict a cross-sectional side elevation view of ashock absorber, in accordance with an embodiment.

FIGS. 9-13 depict a cross-sectional side elevation view of the basevalve assembly of detail 2 of FIG. 1B, including a “latching solenoid”,in accordance with an embodiment.

The drawings referred to in this description should be understood as notbeing drawn to scale except if specifically noted.

BRIEF DESCRIPTION

Reference will now be made in detail to embodiments of the presenttechnology, examples of which are illustrated in the accompanyingdrawings. While the technology will be described in conjunction withvarious embodiment(s), it will be understood that they are not intendedto limit the present technology to these embodiments. On the contrary,the present technology is applicable to alternative embodiments,modifications and equivalents, which may be included within the spiritand scope of the invention as defined by the appended claims.

Furthermore, in the following description of embodiments, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present technology. However, the present technologymay be practiced without these specific details. In other instances,well known methods, procedures, and components have not been describedin detail as not to unnecessarily obscure aspects of the presentdisclosure.

Embodiments describe a system and method for a pilot spool valveassembly that enables the generation of relatively large damping forcesby a relatively small solenoid (or other motive source), while usingrelatively low amounts of power. Furthermore, since the incompressiblefluid inside of the valve body of the shock absorber assembly causesdamping to occur as the valve opens and the valve body collapses,embodiments enable both a controllable preload on the valve stack and acontrollable damping rate.

In one embodiment, the solenoid includes a “latching” mechanism to openand close the pressure-balanced pilot spool. Due to the latchingconfiguration of the solenoid, power is only required to open or closethe valve. Power is not required to hold the valve open or closed ineither setting. Consequently, embodiments enable reduced powerconsumption compared to the traditional shock absorber.

Further embodiments provide an externally-adjustable means of tuning theopen state of the damper. An adjuster turns in or out to vary theeffective orifice size of the pilot spool when in the open position.This allows the rider to adjust the soft setting of the damper to hispreference.

The following discussion describes the FIGS. 1-8B and embodiments showntherein.

Integrated damper/spring vehicle shock absorbers often include a damperbody surrounded by or used in conjunction with a mechanical spring orconstructed in conjunction with an air spring or both. The damper oftenconsists of a piston and shaft telescopically mounted in a fluid filledcylinder. The damping fluid (i.e., damping liquid) or damping liquid maybe, for example, hydraulic oil. A mechanical spring may be a helicallywound spring that surrounds or is mounted in parallel with the damperbody. Vehicle suspension systems typically include one or more dampersas well as one or more springs mounted to one or more vehicle axles. Asused herein, the terms “down”, “up”, “downward”, “upward”, “lower”,“upper”, and other directional references are relative and are used forreference only.

FIG. 1A shows an asymmetric bicycle fork 100 having a damping leg and aspring leg. The damping leg includes an upper tube 105 mounted intelescopic engagement with a lower tube 110 and having fluid dampingcomponents therein. The spring leg includes an upper tube 106 mounted intelescopic engagement with a lower tube 111 and having spring componentstherein. The upper legs 105, 106 may be held centralized within thelower legs 110, 111 by an annular bushing 108. The fork 100 may beincluded as a component of a bicycle such as a mountain bicycle or anoff-road vehicle such as an off-road motorcycle. In some embodiments,the fork 100 may be an “upside down” or Motocross-style motorcycle fork.

In one embodiment, the damping components inside the damping leg includean internal piston 166 disposed at an upper end of a damper shaft 136and fixed relative thereto. The internal piston 166 is mounted intelescopic engagement with a cartridge tube 162 connected to a top cap180 fixed at one end of the upper tube 105. The interior volume of thedamping leg may be filled with a damping liquid such as hydraulic oil.The piston 166 may include shim stacks (i.e., valve members) that allowa damping liquid to flow through vented paths in the piston 166 when theupper tube 105 is moved relative to the lower tube 110. A compressionchamber is formed on one side of the piston 166 and a rebound chamber isformed on the other side of the piston 166. The pressure built up ineither the compression chamber or the rebound chamber during acompression stroke or a rebound stroke provides a damping force thatopposes the motion of the fork 100.

The spring components inside the spring leg include a helically woundspring 115 contained within the upper tube 106 and axially restrainedbetween top cap 181 and a flange 165. The flange 165 is disposed at anupper end of the riser tube 163 and fixed thereto. The lower end of theriser tube 163 is connected to the lower tube 111 in the spring leg andfixed relative thereto. A valve plate 155 is positioned within the upperleg tube 106 and axially fixed thereto such that the plate 155 moveswith the upper tube 106. The valve plate 155 is annular inconfiguration, surrounds an exterior surface of the riser tube 163, andis axially moveable in relation thereto. The valve plate 155 is sealedagainst an interior surface of the upper tube 106 and an exteriorsurface of the riser tube 163. A substantially incompressible lubricant(e.g., oil) may be contained within a portion of the lower tube 111filling a portion of the volume within the lower tube 111 below thevalve plate 155. The remainder of the volume in the lower tube 111 maybe filled with gas at atmospheric pressure.

During compression of fork 100, the gas in the interior volume of thelower tube 111 is compressed between the valve plate 155 and the uppersurface of the lubricant as the upper tube 106 telescopically extendsinto the lower tube 111. The helically wound spring 115 is compressedbetween the top cap 181 and the flange 165, fixed relative to the lowertube 111. The volume of the gas in the lower tube 111 decreases in anonlinear fashion as the valve plate 155, fixed relative to the uppertube 106, moves into the lower tube 111. As the volume of the gas getssmall, a rapid build-up in pressure occurs that opposes further travelof the fork 100. The high pressure gas greatly augments the spring forceof spring 115 proximate to the “bottom-out” position where the fork 100is fully compressed. The level of the incompressible lubricant may beset to a point in the lower tube 111 such that the distance between thevalve plate 155 and the level of the oil is substantially equal to amaximum desired travel of the fork 100.

Referring now to FIG. 1B, a cross-sectional side elevation view of ashock absorber of a bicycle fork cartridge is depicted, in accordancewith an embodiment. More particularly, FIG. 1B shows the inner portionsof the bicycle fork leg assembly, comprising a damper piston 5. Inpractice, the top cap 20 is affixed to an upper tube (not shown) and thelower connector 10 is fixed to a lower leg tube (not shown) where theupper tube is typically telescopically mounted within the lower tube(although the reverse may also be the case). As the upper tube and thelower tube telescope in contraction or expansion in response todisparities in the terrain being traversed by a vehicle, including suchfor shock absorbsion, so also the damper piston 5 and piston rod 15 movetelescopically into and out of damper cylinder 25. During compression,the volume of the piston rod 15 displaces, from the cylinder 25, avolume of damping liquid contained within the cylinder 25 correspondingto the volume of the piston rod 15 incurring into the damper cylinder25. During extension or “rebound”, the volume of liquid must be replacedas the piston rod 15 leaves the interior of the damper cylinder 25.

Damping liquid displaced as described above moves from the dampercylinder 25, through a base valve assembly of detail 2 and ultimatelyinto an elastic bladder 30 during compression, and from the elasticbladder 30, back through the base valve assembly of detail 2 and intothe damper cylinder 25 during rebound. In one embodiment, the base valveassembly of detail 2 allows for the compression damping to be adjustedby the user.

FIG. 2, FIG. 3, and FIG. 4 show cross-sectional side elevation views ofvarious operational positions of an embodiment of the base valveassembly of detail 2 of FIG. 1B. FIGS. 2-4 show a continuously variablesemi active arrangement, in accordance with embodiments, and as will bedescribed in more detail below. In brief, a solenoid balanced by anarmature biasing spring 235 axially locates a pressure-balanced pilotspool 210. The pressure-balanced pilot spool 210 controls the pressureinside the valve body 230. As this pressure is increased inside thevalve body 230, the axially force of the valve body 230 on theconventional valve shim increases. Due to the pilot spool assemblyarrangement, a relatively small solenoid (using relatively low amountsof power) can generate relatively large damping forces. Furthermore, dueto incompressible fluid inside the valve body 230, damping occurs as thevalve opens and the valve body 230 collapses. The result is not only acontrollable preload on the valve stack, but also a controllable dampingrate. Embodiments discussed herein may optionally be packaged in a basevalve, the compression adjuster of a shock absorber, and/or on the mainpiston of a shock absorber.

FIG. 2 is a detailed view of the base valve assembly of detail 2 of FIG.1B, with the valve shown in the retracted soft position. This retractedposition corresponds to minimum or no current in the solenoid. In FIG.2, a first damping fluid flow path between damping cylinder interior 35and annular reservoir 40 (including bladder 30 interior; see FIG. 1B) issubstantially unobstructed via bleed passage 55, ports 50A and upperannulus 45. (Also shown in FIG. 2 is the main piston 245.)

FIG. 3 is a detailed view of the base valve assembly of detail 2 of FIG.1B, with the valve shown in the mid-damping position. This correspondsto medium current supplied to the solenoid. FIG. 3 shows a partialobstruction of ports 50A by metering edge 205 of the pilot spool 210.

FIG. 4 is a detailed view of the base valve assembly of detail 2 of FIG.1B, with the valve shown in the firm-damping position. FIG. 4 showssubstantial blockage of ports 50A by the metering edge 205 of the pilotspool 210, which is axially displaced relative to its position in FIG.2.

Of note, the pilot spool 210 shown in FIG. 2 is in a retracted softposition, in which the metering edge 205 of the pilot spool 210 is notobstructing the ports 50A. However, the pilot spool 210 shown in FIG. 3is in a middle position, in which the metering edge 205 of the pilotspool 210 is partially obstructing the ports 50A. The pilot spool 210shown in FIG. 4 is in a firm position, in which the metering edge 205 ofthe pilot spool 210 is fully obstructing ports 50A.

In one embodiment, the axial displacement of the pilot spool 210 isfacilitated by an electromagnetic interaction between the armature 215and the coil 220. Adjustment of the current in the coil 220 (viamodulation of the current from a power source [not shown]) topredetermined values causes the armature 215, and hence the pilot spool210, to move in corresponding predetermined axial positions relative tothe coil 220. As such, the pilot spool 210 can be adjusted as shown inthe FIGS. 2-4.

When the pilot spool 210 is closing ports 50A, as shown in FIG. 4,substantially all damping fluid compression flow must flow through port70 and valve shims 225. In addition, the damping fluid pressure actingthrough and in annulus 60 on an interior of the valve body 230 isincreased and therefore the valve body 230 exerts more closing force ofthe valve shims 225. The net result is an increased compression dampingdue to closure of ports 50A and a further compression damping increasedue to a corresponding pressure increase in the compression dampingwithin annulus 60. When the pilot spool 210 is located in a middleposition as is shown in FIG. 3, the foregoing results apply in adiminished way because some of the compression flow (albeit less thanfull compression flow) may flow through partially open ports 50A. Theembodiment of FIG. 2 also exhibits some effect of pressure boosting viaannulus 60 on the valve body 230, but the phenomenon occurs at highercompression rates.

FIG. 5A and FIG. 5B depict a cross-sectional side elevation view of avalve assembly of detail 2 of the shock absorber of FIG. 1B, inaccordance with an embodiment. FIG. 5A and FIG. 5B show an embodiment inwhich the valve body 230 acts on the valve shims 225 through a spring75. In use, the valve body 230 increases or decreases the preload on thespring 75. FIG. 5A shows the pilot spool 210 in the retracted softposition, thereby causing the preload on the spring 75 to decrease. FIG.5B shows the pilot spool 210 in the firm position, thereby causing thepreload on the spring 75 to increase.

FIG. 6 and FIG. 7 depict a cross-sectional side elevation view of thevalve assembly of detail 2 of the shock absorber of FIG. 1B, inaccordance with an embodiment. FIG. 6 and FIG. 7 show an embodimentincluding a flow control orifice 605 for limiting flow through into thebleed passage 55 during compression. In limiting fluid flow, the flowcontrol orifice 605 (by creating a pressure drop) places an upper limiton the amount of pressure in the annulus 60, and hence the amount of“boost” or closure force that the valve body 230 can exert on the valveshims 230. FIG. 6 shows the metering edge 205 of the pilot spool 210obstructing ports 50A. FIG. 7 shows the metering edge 205 of the pilotspool 210 partially obstructing ports 50A.

FIG. 8A and FIG. 8B depict a cross-sectional side elevation view of ashock absorber, in accordance with an embodiment. More particularly,FIG. 8A shows an embodiment having a separate valve body 805A and 805Bcorresponding to each of a rebound shim set 810 and a compression shimset 815, respectively, where a pilot spool 820 (performing, in oneembodiment, similarly to the pilot spool 210 of FIGS. 1-7 describedherein) alternatingly opens one area (e.g., 825A [similar to function toannulus 60]) while closing the other area (e.g., 825B [similar infunction to annulus 60]). Of note, FIG. 8A shows a “hard/softconfiguration”. For example, during compression, the area 825A and area825B experience obstruction by a portion of the pilot spool 820, therebycreating a soft compression. During the rebound, the area 825A and area825B are open to fluid flow, thereby creating a firm rebound. Thus,there would be a high amount of pressure experienced during rebound.However, for compression, the pressure is low, but there is no bleed.FIG. 8B shows a “hard/hard configuration” (a firm compression and a firmrebound), in accordance with an embodiment.

FIGS. 9-13 depicts a cross-sectional side elevation view of the basevalve assembly of detail 2 of FIG. 1B, including a “latching solenoid”,in accordance with an embodiment. Embodiments further provide, in briefand as will be described below, a low-power bi-state electronic damper.The low-power bi-state electronic damper uses a latching solenoid toopen and close a pressure-balanced pilot spool. Given the latchingconfiguration of the solenoid, power is required only to open or closebut not to hold in it in either setting, in accordance with anembodiment. The result is low power consumption.

Additionally, a further embodiment provides an externally-adjustablemeans of tuning the open state of the damper. There is an adjuster thatcan be turned in or out to vary the effective orifice size of the pilotspool when in the open position. This will allow the rider to adjust thesoft setting of the damper to his/hers preference.

With reference now to FIG. 9, the latching solenoid 905 primarily usespower to facilitate a change in position of the pilot spool 210 relativeto the coil 220 but requires little or no power to maintain the pilotspool 210 in the desired position once that is achieved. In oneembodiment, the latching solenoid assembly 905 (or latching spool valveassembly) includes: a pilot spool 210 which includes a magneticallyactive material; a spring 915 which is normally in compression andbiases the pilot spool 210 toward a position obstructing ports 50A; apermanent magnet 920; and a coil 220 where power is supplied to the coil220 by (in one embodiment) wires 925. The aforementioned components maybe contained within a housing 240 or “cartridge” as shown.

The pilot spool valve assembly (including at least the pilot spool 210and the metering edge 930 of the pilot spool 210) regulates dampingfluid flow through a portion of the damper and adjusts the force appliedto the valve shims 225 by the valve body 230 through ports 60. In oneembodiment, the position of the spool valve assembly may be adjustedaxially by means of the low speed adjuster 935. The low speed adjuster935 (comprising multiple pieces), being for example, threaded at itslower end to the top cap 20 via the low speed adjuster threads 940, maybe rotated to facilitate axial movement. In one embodiment, the lowspeed adjuster 935 includes a non-round shape (e.g., hexagonal) thatfacilitates the rotation with relative axial movement (see 1105 of FIG.11).

With reference now to FIGS. 9-13, when the lower portion of the lowspeed adjuster 935 moves downward axially, the cartridge of the pilotspool 210 is correspondingly moved and thereby further compresses thespring 915. As the cartridge is moved downward, the low speed adjustermetering edge 950 is moved into further obstruction of ports 50B,thereby restricting flow of damping fluid through the damper from aninterior of the pilot spool valve assembly to an exterior of the dampingassembly (note the open ports 50B shown in FIG. 12, in which the pilotspool valve 210 is shown in the open pilot position with the low speedadjuster 935 in the soft position).

In one embodiment, the pilot spool 210 is biased by spring 915 toward aposition wherein the metering edge 930 of the pilot spool 210 furtherobstructs ports 50A (see FIG. 13, wherein the pilot spool 210 is shownin the open pilot position with the low speed adjuster 935 in the middleposition). A force opposing the bias of the spring 915 is exerted on themagnetic component of the pilot spool 210 by the permanent magnet 920.When the pilot spool 210 is in its uppermost (corresponding to openports 50A) position, it is retained by the magnetic force between thepermanent magnet 920 and the pilot spool valve 210 where that force issufficient to overcome the bias of the spring 915 (thereby holding thespring 915 in a compressed state). As such, when the pilot spool valve210 and ports 50A are in the open position (see FIG. 12), no power inputis required to maintain that state.

In one embodiment, when it is desired to close or partially close ports50A by means of the metering edge 930 of the pilot spool 210, a currentis applied to the coil 220 via the wires 925. The current causes amagnetic flux around the coil 220, which acts on the magnetic componentof the pilot spool 210 causing the pilot spool 210 to move axiallywithin the cartridge. When the pilot spool 210 has moved a relativelysmall distance axially away from the permanent magnet 920, the spring915 bias moves the pilot spool 210 toward closure of ports 50A withlittle or no additional power input to the coil 220.

Of note, FIG. 10 shows the pilot spool 210 in the closed pilot positionwith the low speed adjuster 935 in the firm position. FIG. 11 shows thepilot spool 210 in the open pilot position with the low speed adjuster935 in the firm position. FIG. 10 additionally shows the low speedadjuster metering edge 1005 and the spool valve assembly housing 1010,in accordance with an embodiment.

FIGS. 9-13 show an orifice block 955 having a tailored orifice 960 therethrough. The orifice 960 meters low speed damping fluid for low speedbump response of the suspension (when magnitude and rate is insufficientto open the shims). The size of the orifice 960 may be chosen to allow adesired amount or range of pressure to be applied to the valve body 230through annulus 60 (ports). The use of the pilot spool 210 then furtherspecifies that the pressure acts on the valve body 230 by modulating theflow restriction “downstream” (during a compression stroke of thesuspension) of the orifice 960.

FIGS. 9-13 also show a pressure relief valve 965 or “blow off” valve,which is biased toward a closed position by Bellville spring(s) 970. Thepressure relief valve 965 opens in response to an interior damperpressure above a predetermined threshold and thereby prevents damage tothe damper and vehicle in the event of rapid pressure build up (usuallyassociated with extreme suspension compression rate). The pressurerelief valve 965 may have an adjustable threshold value (in oneembodiment, by modification of the compression in the Bellville spring970).

It should be noted that any of the features disclosed herein may beuseful alone or in any suitable combination. While the foregoing isdirected to embodiments of the present invention, other and furtherembodiments of the invention may be implemented without departing fromthe scope of the invention, and the scope thereof is determined by theclaims that follow.

What is claimed is:
 1. A vehicle suspension damper comprising: a set ofvalve shims through which a damping fluid compression flows; a valvebody configured for exerting a closing force of said set of valve shimsproportionate to a damping fluid pressure acting through and in aannulus on an interior of said valve body; a pilot spool of a pilotvalve assembly, said pilot spool acting on said damping fluid pressure;and a latching solenoid assembly configured for using power tofacilitate a change in a position of said pilot spool, said latchingsolenoid assembly comprising: an armature coupled to a power source,wherein said power source uses power to facilitate a change in aposition of said pilot spool relative to said armature; a magneticallyactive material of said pilot valve assembly; a spring biasing saidpilot spool toward a position obstructing a set of ports; and apermanent magnet configured for exerting a magnetic force on a magneticcomponent of said pilot spool, wherein upon an exertion of said magneticforce, said pilot spool is retained next to said permanent magnet, saidmagnetic force opposes said spring biasing said pilot spool toward saidposition that obstructs said set of ports, and said magnetic force holdssaid spring in a compressed state.
 2. The vehicle suspension damper ofclaim 1, wherein said power source comprises: a solenoid.
 3. The vehicledamper of claim 1, wherein said latching solenoid assembly and arotatable low speed adjuster can be turned in or out to vary aneffective orifice size of said pilot spool when said pilot spool is inan open position.
 4. The vehicle suspension damper of claim 1, furthercomprising: a rotatable low speed adjuster, whereupon rotation of saidlow speed adjuster, an axial movement of said pilot valve assemblyoccurs, wherein upon being retained between said permanent magnet andsaid pilot valve assembly by a magnetic force, said magnetic force issufficient to overcome said spring biasing said pilot spool toward saidposition obstructing said set of ports.
 5. The vehicle suspension damperof claim 1, further comprising: an orifice block having a tailoredorifice there through, said orifice configured for metering low speeddamping fluid for low speed bump response of said vehicle suspensiondamper by allowing a predetermined amount of pressure to be applied tosaid valve body through said set of ports.